Method and apparatus to elevate the engine idle to allow battery charging during the operation of a snow plow or other accessory

ABSTRACT

A vehicle  10  includes an accessory system  40  coupled to an engine control module  26.  The accessory system  40  may, for example, be a snow plow. The accessory system  40  is coupled to a first pin  30  and a second pin  32  of the engine control module. When both of the pins are high, the idle speed of an engine  12  is raised so that the speed of the alternator  14  is raised so that a battery  16  may maintain a charging level on the battery.

TECHNICAL FIELD

The present invention relates generally to a control system, and more particularly to an engine control system that recognizes an accessory and boosts the idle speed of the engine to allow battery charging.

BACKGROUND

Various accessories such as snow plows are commonly attached to heavy duty vehicles. In the case of snow plows, the snow plows are operated with hydraulic systems that draw power from the vehicle. Snow plows are often used at very low vehicle speeds. The low vehicle speeds correspond to a low engine rotation speed. If the speed of the engine is too low, the battery will not charge. During the operation of a snow plow the blade is typically manipulated in various positions at the low speed and may cause the battery to completely discharge.

It would therefore be desirable to recognize the operation of an accessory and increase the engine speed to maintain the battery in a charging state.

SUMMARY

The present invention provides a vehicle system that includes an engine control module and an accessory coupled to the first pin and the second pin of an engine control module. The engine control module increases the idle speed of the engine in response to the first pin and second pin being high.

In a further aspect of the invention, a method of operating a vehicle comprises determining when a first pin and a second pin of an engine control module connector is coupled high by an accessory and increasing in idle speed in response to the first pin and second pin being high.

One advantage of the invention is that the system operates when the vehicle is in a driving mode. That is, a parking mode is not required for elevated engine RPM within the calibratable limits.

Other advantages and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a vehicle having a control system according to the present invention.

FIG. 2 is a flow chart illustrating a method for operating the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following figures are described with respect to a snow plow accessory. However, those skilled in the art will recognize that various other accessories used during operation of the vehicle may be employed.

Referring now to FIG. 1, a vehicle 10 is illustrated having an engine 12 that is coupled to an alternator 14. The alternator 14 is coupled to battery 16. Although battery 16 is illustrated as two different boxes, one battery is typically provided on a vehicle. As the engine 12 rotates, alternator 14 spins and generates electricity. When the alternator is above a speed the alternator acts as a generator and generates power to charge the battery 16. The engine 12 is coupled to a transmission 20 that has an output corresponding to the state of the vehicle. For example, the transmission 20 may generate an output corresponding to a drive or driven mode. This is in contrast to other modes such as a reverse mode and a park mode.

An engine control module (ECM) 26 is coupled to the engine 12 and controls the engine 12 according to various parameters of the vehicle. Engine control module 26, for example, controls the engine idle speed. The engine control module 26 includes an engine control module connector 28 that may, for example, have a battery charge protect pin 30 and a powertrain takeoff pin 32. Of course, various other pins may be used to couple information to or from the engine control module 26. The engine control module 26 may also be coupled to a fan 33 and a parking brake 36. The engine control module 26 may control the speed of the fan 33 and may also receive information regarding the activation or disconnection of the parking brake 36.

The battery charge protect (BCH) pin 30 and the power takeoff (PTO) pin 32 are referred to respectively as a first pin and a second pin. An accessory system 40 may be coupled to the first pin 30 and the second pin 32 through a connector 42. Both pins 30 and 32 may be coupled to a run feed 44 and a snow plow switch 46. When an accessory such as a snow plow 58 is desired to be operated, the snow plow switch 46 is closed and both pins or battery charge protect pin 30 and PTO pin 32 are connected to run feed 44. The run feed 44 is energized with the battery 16 when the vehicle ignition is on. When the vehicle ignition is off, the run feed 44 is no longer activated.

The accessory 40 may have a module such as a snow plow module 48. The snow plow module may be coupled to snow plow switch 46. When it is desired that the snow plow be activated, the snow plow module 48 may be coupled to battery 16 through a switch 50. When the first pin 30 and the second pin 32 receive a high indication, the engine control module increases the idle speed of the engine. For example, the idle speed may be increased by about 200 rpm so that battery charging may be performed. The amount of increase depends on many conditions including the type of engine, the type or output of the alternator, and the amount of power required by the accessory. In addition, the speed of fan 33 may be changed to cool the engine when an accessory is provided. In one example, when both the first pin 30 and the second pin 32 are high, the fan speed 32 may be increased to allow further engine cooling. Engine cooling may also be increased in response to a parking brake 36. When the parking brake 36 generates a signal indicating the parking brake is off, the engine control module may increase the speed of fan 33. This may be performed in conjunction with monitoring the pins 30 and 32.

It should be noted that high refers to a power on or battery voltage mode in this case. It should be noted that a high condition may be anything but a ground condition or disconnected condition. That is, both a high battery voltage or reverse battery voltage, or voltages less than the battery voltage, may be used to indicate a high condition.

The snow plow module 48 is coupled to an actuator 56 which moves the snow plow blade 58. The actuator 56 requires a significant amount of energy to move the blade 58 into various positions. Thus, when both of the pins 30 and 32 are high, the engine speed is increased so that the alternator spins at a sufficient speed to maintain a charge in the battery 16.

Referring now to FIG. 2, a method for operating the invention is illustrated. In step 100, the pin status is checked along with the base idle and vehicle speed. All three conditions in step 100 may be checked or polled periodically by the engine control module 26. In step 102, when the two pins of interest are not high or vehicle speed is greater then zero or the idle speed is greater then base idle, the system returns to step 100 and rechecks the entry conditions. In step 102, if the pins are high and vehicle speed is equal to zero and idle speed is equal to base idle, this indicates an accessory such as a snow plow is coupled to the vehicle and snow plow mode is enabled. In step 104, if all three conditions are met, the engine idle speed is elevated by a predetermined amount. As mentioned above, the predetermined amount may be about 200 rpms. The amount may vary depending on the engine. What is important is that the engine idle speed is maintained at a level to allow the alternator to charge or maintain the battery charge level.

In step 106, an optional step of changing the fan speed may also be performed. The fan speed may be changed based on various conditions such as the mere fact that an accessory is coupled by monitoring the pin or by monitoring the status of other components such as the parking brake 36, or the like. For example, when the power takeoff pin 32 is high and the brake is not set, the fan may be maintained at least at a minimum rpm or above. Changing the fan speed allows the engine to cool due to the increased heat generated at the higher speed since vehicle movement may not provide enough cooling.

While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims. 

1. A vehicle system comprising an engine control module; and an accessory coupled to a first pin and a second pin of the engine control module; said engine control module increasing an idle speed in response to the first pin and the second pin being high.
 2. A vehicle system as recited in claim 1 wherein said engine control module increasing an idle speed in response to the first pin and the second pin being high when the vehicle is in a drive mode.
 3. A vehicle system as recited in claim 1 wherein the accessory is a snow plow module and a snow plow switch.
 4. A vehicle system as recited in claim 1 wherein the snow plow switch is coupled to a run feed.
 5. A vehicle system as recited in claim 1 wherein increasing an idle speed comprises increasing the idle speed by a predetermined speed.
 6. A vehicle system as recited in claim 1 further comprising an engine fan having an engine fan speed, wherein said engine control module changes an engine fan speed when the first pin and the second pin are high.
 7. A vehicle system as recited in claim 1 further comprising an engine fan having an engine fan speed, wherein said engine control module changes an engine fan speed when the first pin and the second pin are high and a parking brake is off.
 8. A method of operating a vehicle system comprising: determining when a first pin and a second pin of the engine control module connector is coupled high by an accessory; and increasing an idle speed in response to the first pin and the second pin being high.
 9. A method as recited in claim 8 wherein the accessory comprises a snow plow.
 10. A method as recited in claim 8 wherein the accessory comprises a snow plow module and a snow plow switch.
 11. A method as recited in claim 10 wherein the snow plow switch is coupled to a run feed.
 12. A method as recited in claim 8 wherein increasing an idle speed comprises increasing the idle speed by a predetermined speed.
 13. A method as recited in claim 8 further comprising changing an engine fan speed when the first pin and the second pin are high.
 14. A method as recited in claim 8 further comprising changing an engine fan speed when the first pin and the second pin are high and a parking brake is off.
 15. A method of controlling a vehicle comprising: coupling a snow plow switch to a vehicle first pin and second pin; and when the first pin and the second pin are high, increasing the idle speed of the vehicle by a predetermined speed.
 16. A method as recited in claim 15 wherein the first vehicle pin and the second vehicle pin are coupled to the engine control module.
 17. A method as recited in claim 15 wherein the predetermined speed is about 200 rpms.
 18. A method as recited in claim 15 further comprising changing an engine fan speed when the first pin and the second pin are high.
 19. A method as recited in claim 15 further comprising changing an engine fan speed when the first pin and the second pin are high and a parking brake is off.
 20. A method as recited in claim 15 wherein the snow plow switch is coupled to a run feed. 